<template lang="html">
  <div>
  <div class="goods">
    <!-- menu-wrapper -->
    <div class="menu-wrapper" ref="menuWrapper">
      <ul>
        <li v-for="(item, $index) in goods" class="menu-item" :class="{'current': currentIndex === $index}" @click="selectMenu($index, $event)">
          <span class="text border-1px">
            <span v-show="item.type>0" class="icon" :class="classMap[item.type]"></span>{{item.name}}
          </span>
        </li>
      </ul>
    </div>
    <!-- foods-wrapper -->
    <div class="foods-wrapper" ref="foodsWrapper">
      <ul>
        <li v-for="(item, $index) in goods" class="food-list food-list-hook">
          <h1 class="title">{{item.name}}</h1>
          <ul>
            <li @click="selectFood(food, $event)" v-for="(food, $index) in item.foods" class="food-item border-1px">
              <div class="icon">
                <img :src="food.icon" width="57" height="57">
              </div>
              <div class="content">
                <h2 class="name">{{food.name}}</h2>
                <p class="desc">{{food.description}}</p>
                <div class="extra">
                  <span class="count">月售{{food.sellCount}}份</span>
                  <span>好评率{{food.rating}}%</span>
                </div>
                <div class="price">
                  <span class="now">￥{{food.price}}</span>
                  <span class="old" v-show="food.oldPrice">￥{{food.oldPrice}}</span>
                </div>
                <div class="cartcontrol-wrapper">
                  <cartcontrol :food="food"></cartcontrol>
                </div>
              </div>
            </li>
          </ul>
        </li>
      </ul>
    </div>
    <!-- shopcart -->
    <shopcart ref="shopcart" :select-foods="selectFoods" :delivery-price="seller.deliveryPrice" :min-price="seller.minPrice"></shopcart>
  </div>
  <food :food="selectedFood" ref="food"></food>
  </div>
</template>

<script>
import BScroll from 'better-scroll';
import shopcart from '../shopcart/shopcart.vue';
import cartcontrol from '../cartcontrol/cartcontrol.vue';
import food from '../food/food.vue';
import {eventHub} from 'common/js/eventHub';
const ERR_OK = 0;

export default {
  name: 'goods',
  props: {
    seller: {
      type: Object
    }
  },
  data() {
    return {
      goods: [],
      listHeight: [],
      scrollY: 0,
      selectedFood: {}
    }
  },
  computed: {
    currentIndex() {
      for (let i = 0; i < this.listHeight.length; i++) {
        let height1 = this.listHeight[i];
        let height2 = this.listHeight[i + 1];
        if(!height2 || (this.scrollY >= height1 && this.scrollY < height2)) {
          return i;
        }
      }
      return 0;
    },

    selectFoods() {
      let foods = [];
      this.goods.forEach((good) => {
        good.foods.forEach((food) => {
          if(food.count) {
            foods.push(food);
          }
        });
      });
      return foods;
    }
  },
  created() {
    this.classMap = ['decrease', 'discount', 'special', 'invoice', 'guarantee'];

    this.$http.get('/api/goods').then((response) => {
      response = response.body;
      if(response.errno === ERR_OK) {
        this.goods = response.data;
        this.$nextTick(() => {
          this._initScroll();
          this._calculateHeight();
        });
      }
    });

    // 对应子组件emit调用
    eventHub.$on('cart.add', (target)=> {
      this._drop(target);
    });
  },
  methods: {
    selectMenu(index, event) {
      if(!event._constructed) {
        return;
      }
      let foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook');
      let el = foodList[index];
      this.foodsSCroll.scrollToElement(el, 300);
    },
    // 显示食物详情
    selectFood(food, event) {
      if(!event._constructed) {
        return;
      }
      this.selectedFood = food;
      this.$refs.food.show();
    },
    // 体验优化,异步执行下落动画
    _drop(target) {
      this.$nextTick(() => {
        this.$refs.shopcart.drop(target);
      });
    },
    _initScroll() {
      this.menuScroll = new BScroll(this.$refs.menuWrapper, {
        click: true
      });

      this.foodsSCroll = new BScroll(this.$refs.foodsWrapper, {
        click: true,
        probeType: 3
      });

      this.foodsSCroll.on('scroll', (pos) => {
        this.scrollY = Math.abs(Math.round(pos.y));
      });
    },
    _calculateHeight() {
      let foodList = this.$refs.foodsWrapper.getElementsByClassName('food-list-hook');
      let height = 0;
      this.listHeight.push(height);
      for(let i=0; i<foodList.length; i++) {
        let item = foodList[i];
        height += item.clientHeight;
        this.listHeight.push(height);
      }
    }
  },
  components: {
    shopcart,
    cartcontrol,
    food
  }
}
</script>

<style lang="scss">
  @import "../../common/scss/default";
  @import "../../common/scss/mixin";

  .goods {
    display: flex;
    position: absolute;
    top: 174px;
    bottom: 46px;
    width: 100%;
    overflow: hidden;
    .menu-wrapper {
      flex: 0 0 80px;
      width: 80px;
      background: $silvery;
      .menu-item {
        display: table;
        height: 54px;
        width: 56px;
        padding: 0 12px;
        line-height: 14px;
        &.current {
          position: relative;
          z-index: 10;
          margin-top: -1px;
          background: $white;
          font-weight: 700;
          .text {
            @include border-none();
          }
        }
        .icon {
          display: inline-block;
          vertical-align: top;
          width: 12px;
          height: 12px;
          margin-right: 2px;
          background-size: 12px 12px;
          background-repeat: no-repeat;
          &.decrease {
            @include bg-image('./images/decrease_3');
          }
          &.discount {
            @include bg-image('./images/discount_3');
          }
          &.guarantee {
            @include bg-image('./images/guarantee_3');
          }
          &.invoice {
            @include bg-image('./images/invoice_3');
          }
          &.special {
            @include bg-image('./images/special_3');
          }
        }
        .text {
          display: table-cell;
          width: 56px;
          vertical-align: middle;
          @include border-1px(rgba($grey, 0.1));
          font-size: 12px;
        }
      }
    }
    .foods-wrapper {
      flex: 1;
      .title {
        padding-left: 14px;
        height: 26px;
        line-height: 26px;
        border-left: 2px solid $silvery2;
        font-size: 12px;
        color: $grey2;
        background: $silvery;
      }
      .food-item {
        display: flex;
        margin: 18px;
        padding-bottom: 18px;
        @include border-1px(rgba($grey, .1));
        &:last-child {
          @include border-none();
          margin-bottom: 0;
        }
        .icon {
          flex: 0 0 57px;
          margin-right: 10px;
        }
        .content {
          flex: 1;
          .name {
            margin: 2px 0 8px 0;
            height: 14px;
            line-height: 14px;
            font-size: 14px;
            color: $grey;
          }
          .desc,
          .extra {
            line-height: 10px;
            font-size: 10px;
            color: $grey2;
          }
          .desc {
            line-height: 12px;
            margin-bottom: 8px;
          }
          .extra {
            .count {
              margin-right: 12px;
            }
          }
          .price {
            font-weight: 700;
            line-height: 24px;
            .now {
              margin-right: 8px;
              font-size: 14px;
              color: $red;
            }
            .old {
              text-decoration: line-through;
              font-size: 10px;
              color: $grey2;
            }
          }
          .cartcontrol-wrapper {
            position: absolute;
            right: 0;
            bottom: 12px;
          }
        }
      }
    }
  }
</style>
